Speargun

ABSTRACT

A sportfishing speargun is sized for ease of use and provides the power of the largest rubber band speargun. The speargun includes a drive system with two or more pulleys, the drive system is driven by one or more rubber bands to provide mechanical advantage and the force of a large speargun in a compact device.

This application claims priority to U.S. Provisional Application62/660,457, filed Apr. 20, 2018.

FIELD OF THE INVENTIONS

The inventions described below relate to the field of rubber bandpowered spearguns for sportfishing.

BACKGROUND OF THE INVENTIONS

Conventional rubber band powered spearguns are either large and unwieldyor small and underpowered.

SUMMARY

The devices and methods described below provide for a sportfishingspeargun that is easy to load, maneuver and aim and provides the powerof the largest rubber band speargun with a clear line of sight to aim bymoving the drive mechanism below the spear. The speargun includes adrive system with one or more pulleys driven by one or more rubber bandsto provide mechanical advantage and the force of a large speargun in acompact device. The speargun design moves the drive system beneath thespear and out of the target view. This configuration enables the use ofany number of power bands because all of them are situated underneaththe stock where they do not obscure the shooters view of the target overthe top of the speargun.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a speargun.

FIG. 2 is a bottom view of the speargun of FIG. 1 with the lowercarriage rail removed for clarity.

FIG. 3 is a side view of a cascade drive mechanism for a speargun.

FIG. 4 is a side view of another alternate drive mechanism for aspeargun.

FIG. 5 is a side view of a variation of the alternate drive mechanism ofFIG. 4.

FIG. 6 is a top view of the speargun of FIG. 5.

FIG. 7 is a close up view of the drive wheels of the speargun of FIG. 5.

FIG. 8 is a side view of a speargun with an alternate drive system.

FIG. 9 is an enlarged cross-section of the drive wheel of the speargunof FIG. 8 taken along A-A.

DETAILED DESCRIPTION OF THE INVENTIONS

FIG. 1 is a side view of speargun 1 which includes stock 2 having aprimary grip 2A, optional side handle 3 and drive system 23. The stocksupports and guides spear 4 which is propelled by cable 5. The cable istensioned by one or more rubber bands such as rubber band 6 and therubber bands are anchored to peg or finger 7 extending from stock 2. Thestock also includes trigger assembly 8 which engages and controls therelease of spear 4 using any suitable configuration. The optional sidehandle 3 may be attached to either side of the stock to accommodateeither left or right hand use as illustrated in FIG. 2. The optionalside handle 3 may also be attached at any suitable location between theprimary grip 2A and the fixed pulleys 13L and 13R.

Drive system 23 includes cable 5 secured to the stock at anchor point 10and fixed pulleys and carriage 15 powered by rubber band 6. The cableextends from anchor point 10 around carriage pulleys 12L and 12R andthen around fixed pulleys 13L and 13R and it extends along the stock toengage spear 4 using any suitable configuration such as a slot or pinsuch as pin 14.

Carriage 15 includes axle 16 secured between carriage pulleys 12L and12R. One or more rubber bands such as rubber band 6 are operablyconnected to carriage 15 using hook 17 or any other suitableconfiguration. Stock 2 includes carriage slot 18 to control the travelof carriage 15 as the rubber bands contract to pull the cable and launchthe spear from the speargun. Carriage slot 18 includes stop spring 19Ato stop and cushion the movement of the carriage at the end of itstravel and rebound spring 19B to prevent the carriage fromunintentionally moving back along the carriage slot after compressingstop spring 19A.

To load, a user inserts and secures spear 4 into speargun 1 with triggerassembly 8 engaged to hold the spear in the speargun. Carriage 15 ismoved into loaded position 20 which permits cable 5 to extend around thecarriage pulleys and the fixed pulleys to engage spear 4. One or morerubber bands are secured to hook 17 and then stretched to engage finger7 to provide motive force for launching the spear. To fire the speargun,a user squeezes trigger 8T to cause the trigger assembly to releasespear 4. With the spear free to move, the tension applied by the one ormore rubber bands to carriage 15 through hook 17 causes the carriage tomove along longitudinal axis 21 from loaded position 20 to finishposition 22. As carriage 15 moves toward the finish position, cable 5 ispulled through the fixed pulleys to propel the spear from the speargun.The compound arrangement of fixed pulleys 13L and 13R and the carriagepulleys 12L and 12R magnifies the propulsive power of the rubber bandsused to propel the spear.

FIG. 3 is a side view of a cascade drive system 30 for a speargun. Thecable 5 extends from anchor point 10 around carriage pulleys 12L and 12Rand then around fixed pulleys 13L and 13R and it extends along the stockto engage spear 4 as discussed above. A second stage carriage 31 isoperably secured between primary carriage 15 and any suitable motivepower such as one or more rubber bands 6. Drive cable 32 is secured tothe stock at anchor point 33 and then drawn around secondary drivewheels 34R and 34L and further secured to hook 17. Second stage carriage31 is operably connected to secondary hook 35 as in carriage 15.Secondary hook 35 connects any suitable motive power such as rubber band6 to the second stage carriage.

FIG. 4 is a side view of ratio drive system 40 for a speargun. Primaryor spear cable 5 engages spear 4 as discussed above and the cable passesaround fixed pulleys 13L and 13R and it is secured to outer take-upreels 41L and 41R at attachment points 42L and 42R respectively. Ratiodrive system 40 is formed by axle 43 secured to outer take up reels 41Land 41R and inner drive wheels 44L and 44R. The energy supplied byrubber band 6 is multiplied by the ratio between the radius of the outertake up wheel, radius 45 and the radius of the inner drive wheel 46. Oneor more rubber bands such as rubber band 6 are operably connected todrive cable 47 using any suitable techniques such as hook 48. Drivecable 47 is connected to the inner drive wheel and is wound around theinner drive wheel when the speargun is loaded.

Drive cable 47 is preferably a thin and flat element to prevent thegrowth of the drive radius as cable 47 is wound around the inner drivewheels 44R. Conversely, drive cable 5 is preferably a thick cable with around cross section and outer take up reels 41L and 41R have narrowslots for engaging the drive cable 5 to force the drive cable to windover itself when loading the speargun to increase the radial differencebetween the inner drive wheel radius 46 and the outer take up wheelradius 45 and thus, to increase the initial torque of the drive systemwhen the trigger is released.

In use, a user operates the trigger of the speargun releasing the spear.The motive tension provided by the rubber bands applies a force 49 tothe drive cable causing the inner drive wheel to turn. The turning ofthe inner drive wheel causes the take up wheel to turn which pulls oncable 5 which is wound on the take up wheel. The force applied to cable5 causes the spear to be launched from the speargun.

FIGS. 5, 6 and 7 illustrate a first variation of the ratio drive system40 of FIG. 4. Speargun 50 includes ratio drive system 51 secured tostock 52. Ratio drive system 51 separates left and right drivecomponents 51R and 51L and secures them on horizontal wings 53R and 53Lrespectively. Primary or spear cable 5 engages spear 4 as discussedabove and the cable is secured to upper take-up reels 54L and 54R. Ratiodrive system 40 is formed by right axle 55 and left axle 56 secured toupper take up reels 54R and 54L and lower drive wheels 57R and 57Lrespectively. The energy supplied by rubber band 6 is multiplied by theratio between the radius of the upper take up wheel, radius 58 and theradius of the lower drive wheel, radius 59. One or more rubber bandssuch as rubber band 6 are operably connected to drive straps such asstraps 60R and 60L using any suitable technique. The drive straps areconnected to the lower drive wheel and are wound around the lower drivewheel when the speargun is loaded. The optional side handle 3 may alsobe attached at any suitable location on the stock between the primarygrip 2A and the fixed pulleys 13L and 13R.

In use, a user operates the trigger of the speargun releasing the spear.The motive tension provided by the rubber bands applies a force 61 tothe drive straps causing the lower drive wheel to turn. The turning ofthe lower drive wheel causes the upper take up wheel to turn which pullson cable 5 which is wound on the upper take up wheel. The force appliedto cable 5 causes the spear to be launched from the speargun.

FIGS. 8 and 9 illustrate a second variation of the ratio drive system 40of FIG. 4. Speargun 66 includes ratio drive system 67. Primary or spearcable 5 engages spear 4 as discussed above and the cable passes aroundfixed pulleys 13L and 13R and it is secured to outer take-up reels 68Land 68R respectively. Ratio drive system 67 is formed by drive spool 69secured to outer take up reels 68L and 68R which are supported from thestock by fingers 2L and 2R. The energy supplied by rubber band 6 throughdrive cable 72 to the drive spool 69 is multiplied by the ratio betweenthe radius of the outer take up reel, radius 70 and the radius of thedrive spool, radius 71. One or more rubber bands such as rubber band 6are operably connected to drive cable 72 using any suitable techniquessuch as hook 73. Drive cable 72 is connected to the drive spool and iswound around the drive spool when the speargun is loaded. Pretensionband 74 maintains suitable tension in the drive system. As discussedabove the optional side handle 3 may also be attached at any suitablelocation between the primary grip 2A and the fixed pulleys 13L and 13R.

Drive cable 72 is preferably a thin and flat element to prevent thegrowth of the drive radius as cable 72 is wound around the spool 69.Conversely, drive cable 5 is preferably a thick cable with a round crosssection and outer take up reels 68L and 68R have narrow slots forengaging the drive cable 5 to force the drive cable to wind on top ofitself when loading the speargun to increase the radial differencebetween the inner drive wheel radius 71 and the outer take up wheelradius 70 and thus, to increase the initial torque of the drive systemwhen the trigger is released.

While the preferred embodiments of the devices and methods have beendescribed in reference to the environment in which they were developed,they are merely illustrative of the principles of the inventions. Theelements of the various embodiments may be incorporated into each of theother species to obtain the benefits of those elements in combinationwith such other species, and the various beneficial features may beemployed in embodiments alone or in combination with each other. Otherembodiments and configurations may be devised without departing from thespirit of the inventions and the scope of the appended claims.

I claim:
 1. A speargun comprising: a stock having a primary grip; adrive system having a plurality of pulleys operably connected between adrive cable and one or more rubber bands; the drive cable operable toeject a spear from the stock; and a carriage slot in the stock; whereinthe drive system comprises; two pulleys secured to the stock; a firstcarriage operably secured in the carriage slot, the first carriagehaving two pulleys secured to an axle wherein the rubber bands areoperably connected to the axle; wherein the drive cable is operablysecured to the stock and extends around the pulleys on the firstcarriage and around the pulleys secured to the stock and engages thespear.
 2. The speargun of claim 1 further comprising: a second carriageoperably secured in the carriage slot, the second carriage having twopulleys secured to an axle wherein the rubber bands are operablyconnected to the axle of the second carriage instead of the firstcarriage; a second stage drive cable secured to the stock and extendingaround the pulleys on the second carriage and secured to the axle of thefirst carriage.
 3. The speargun of claim 2 further comprising: a sidehandle operatively engaging the stock.
 4. The speargun of claim 1further comprising: a side handle operatively engaging the stock.
 5. Aspeargun comprising: a stock having a primary grip; a drive cableoperably connected between a plurality of drive pulleys and one or morerubber bands; a primary cable operably connected between the drivepulleys and a spear, the drive cable operable to eject the spear fromthe stock.
 6. The speargun of claim 5 further comprising: a side handleoperatively engaging the stock.